1. Field of the Invention
The present invention relates to a rotary agricultural combine having an axially aligned rotor and housing in which at least a portion of the rotor is provided with a plurality of spaced apart tines with at least one ramp segment between the tines that provides an inclined face to urge the grain radially outward from the rotor body.
2. Description of the Related Art
Rotary combines, such as those disclosed in U.S. Pat. Nos. 5,445,563 and 5,688,170, assigned to the Assignee of the present application, include a single rotor within a rotor housing having threshing and separating sections. Other rotary combines, such as those disclosed in U.S. Pat. No. 4,936,810 have two rotors arranged side-by-side. These two rotors also have threshing and separating sections.
The Assignee of the present application has also developed and markets a hybrid combine having a conventional transverse threshing cylinder and a rotary separator. This hybrid system is illustrated in U.S. Pat. No. 5,112,279. The separator unit disclosed in that patent comprises a rotor housing having a pair of side-by-side rotors therein.
The rotors in the above patents contain crop engaging elements about the periphery of the rotor body. In U.S. Pat. No. 5,688,170, the crop engaging elements on the separating portion of the rotor are finger-like tines projecting radially outward from the rotor body. The tines penetrate the crop material and pull the crop material around the rotor, rather than pushing the material as is typical of other rotary combines. This pulling action prevents the material from rolling and forming ropes of material or slugs that may jam the separator. Due to the shape of the rotor housing, the crop material is initially engaged by the tines, rotated and then released as the crop material is thrown upwardly against crop directing vanes on the upper portion of the rotor housing. The vanes drive the crop material rearwardly. The releasing of the crop material is due to the centrifugal force lifting the crop material off the tines into the space located above the rotor that is formed by a non-concentric housing. Separation of the grain from the crop material is accomplished by the grain moving radially outward through grates at the bottom of the rotor housing.
The processing capacity of the combine can be increased by improving the ability of the combine to separate the grain from the crop material. Then, more crop material can be processed by the separator without decreasing the efficiency of the separator, i.e. without losing more grain out the rear of the combine.
It is a feature of the combine of the present invention that the separator capacity is increased by providing the rotor with one or more radially projecting ramp segments intermixed with the spaced apart tines. The ramp segments provide an inclined face that directs the grain radially outward as the ramp segments move through the crop material. The ramp segments provide a face that is trapezoidal in shape, having inwardly inclined front and rear edges such that the radially outer edge of the ramp face is shorter than the inner edge of the face. The trapezoidal shape of the ramp segments facilitates shedding of crop material and thereby prevents the crop material from being entangled on the ramp segments.
Initial testing has shown the ramp segments to be most beneficial in small grain harvesting. The testing has also shown the greatest increase in separating capacity when the number of ramp segments is in the range of approximately 25% to 50% of the number of tines. As the number of ramp segments increases, so does the power required to turn the rotor.